Inductance system



June l0, '1930. L, A. GEBHARD 1,753,233

` Innuc'rwc SYSTBI Filed laren 9. 1929 3 shets-sneet 1 @Www x 5 K Y l g3fi IIIII Il Jmxmloz am Aafblmrl Jur-1e 10, 1930. 'n j L. A. GEBHARDv1,763,233

INDUCTANCE SYSTEM Filed March s, "1929 s sheets-sheet 2 gwuentoz June10, 1930.

3 Sheets-Sheet y Patented June l0, 1930 UNITED STATES PATENT OFFICELOUIS A. GERHARD, F WASHINGTON, DISTRICT 0F COLUMBIA, ASSIGNOB TO WIREDRADIO, INC., OF NEW YORK, N. Y., A CORPORATION OF DELAWARE INDUCTANCESYSTEM Application led March 9, 1929. Serial No. 845,741.

My invention relates to inductance systems in general andmorespecifically to inductance systems employed in high frequency signaling.v

An object of my invention is to provide an inductance system wherein theinductance is cooled by a circulatory liquid and whereby changes in thefrequenc characteristics may be easilyl and readily e ected.

Another object of my invention is to provide an inductance systemwherein a plurality of individual inductances cooled by a circulatoryliquid may be selectively associated with external circuits.

Other and further objects of my invention are to provide certainstructural features of thel inductance system whereby the adaptabilityand efficiency of such systems are increased.

A better understanding of my invention can be had by referring to thespecification following and to the accompanying drawings wherein:

Figure 1 is a perspective view of the inductance system of my invention;Fig. 2 shows a section of a modification of the inductance system of myinvention; Fig. 3 shows a part section of a modified form of theinductance system; and Fig.v 4 shows an end view in part section of theinductance system of my invention. v

In high power transmitters employed in high frequency signaling systemsit is necessary to provide some protection against excessive heating ofthe inductances. The area of the inductance member may be increased thusexposing greater radiatin surface for the excessive temperature. ispractice, however, is not satisfactory due to the increased capacityresulting fromV the increased area. A better solution of the problem isto provide metal tubing or tubing comprising alloys of metalwherethrougha cooling liquid is causedfto circulate. Diiiculty is experienced inattempting to provide an inductance system adaptable to a variety ofcircuits and .a wide frequency band. The inductance system of myinvention avoids the foregoing 'sadvantages and. diilicultiesexperienced with other systems. c

Fig. 1 of the drawings is an illustration showing a perspective view ofthe inductance system of my invention. The inductance system in itsentirety is mounted on a common base 14. A plurality of individualinductance coils are employed herein represented by inductance coils 1,2, 3 and v4. Inductance. coils 1, 2, 3 and 4 comprise suitable lengthsof metal tubing or other members having a passage therethrough for thecirculation of a liquid. Inductance coils 1,2, 3 and 4 are supported bysupporting coil forms or spacers 5, 6, 7 and 8 respectively. Spacers 5,6, 7 and 8 are supported by star shaped end members 9 and 10. A commonshaft 11 extends through and is positioned to members 9 and 10. Shaft 11is supported by upstanding members 12 and 13, the latter provided withsuitabley bearings to permit the rotation of shaft 11. An indicatingdial 15 is positioned to shaft 11 by means of which the particular coilconnected to the external circuit may be ascertained.

Coils 1, 2, 3 and 4 are interconnected by members 16, 17 and 18. Members16, 17 and 18 may comprise lengths of rubber tubing or other suitableinsulating material. Such interconnecting of coils 1, 2, 3 and 4provides a circulating system for a cooling medium I which may notconstitute an electrical interconnection. An electrical conductingmaterial may be employed to advantage Where the inductance connected inthe circuit would be energized from a local source of electrical and theinductance not in use at the particular time serving as a hi l1frequency choke coil. The circulation o the cooling fluid is continuousthrough coils 1,. 2, 3 and 4 since the coils `are connected in vseriesvarrangement for the circulation of the fluid. This arrangement servesto maintain coils 1, 2, 3 and 4 at substantially uniform temperaturesirrespective ofthe particular coil connected to the high vfrequencycircuit. A length of flexible tubing 20 is coiled around shaft 11 andconnected to one end of coil 4. A` length of flexible tubing 21 iscoiled around shaft ll'and connected to coil 3. The coolin liquid iscaused to circulate through ilexib e coil 20, metallic coil4, conductor18, coil y l, conductox'l, coil. `2,c`onductor 17, coil 3 and outthrough flexible coil 21. The circulation may be in the reverse order orin any manner suitable.

Contact members 23, 24, 25 and 26 are positioned to inductance coils 1,2, 3 and 4 respectively and revolve with the coils. Members 23, 24, 25and 26 are positioned on inductance coils 1, 2, 3 and 4 respectively atthe proper turns to give the various inductance values desired. Members23, 24, 25 and 26 are adapted to engage with contact members 27 and 28when coils 1, 2, 3 and 4'are rotated.

Fig. 1 of the drawings shows members 24 engaged with members 27.lInductance coil 2 is connected to the operating circuit at thisadjustment. Indicating dial 15 indicates that coil 2 is in the circuit.Rotating shaft l1 through ninety degrees or one fourth circle, engagesmembers 23 with members 27 and 27 a. Members 23 are positioned to coil1.and indicating dial 15 would show that this coil is connected in thecircuit. In like manner coils 3 and 4 may be rotated whereby theirrespective Contact members are connected to the operating circuit. Anynumber of coils may be arranged to engage with the stationary contactmembers and each of the coils may be provided with as many contactmembers as are desired. Stationary Contact members 27, 272L and 28 aresupported by an insulating member 29 and each may be provided with anadjustment screw 50 to secure the same in the required positions. Member29 is supported by angle members from supporting member 30. The ends ofthe copper coils 1, 2, 3 and 4 may be provided witlrcouplings forconnecting the insulating tubing to the coils. The connections for fluidconduction between the coils may be made with the insulating tubing andthe coils may be arranged so that the fluid paths are either in seriesor in parallel. rlfhe inlet and outlet fluid connections to the group ofcoils are made with insulating tubing 2O and 21 wound in the form of acoil around the shaft 11. Shaft 11 may be of insulating material.Sufficient tubing may be wound around the shaft to permit a highresistance path between the coils and ground where it is necessary forthe coils to be at a high potential. This is the case where the coilsare used in the out put circuit of a thermionic tube and where a seriesfeed system is used for the anode power supply.

Fig. 2 of the accompanying drawings shows in part a modification of theinductance system of my invention. Coil 1 of suitable vmetallic tubingis shown in part section. The several turns of coil 1 are wound on form5 of suitable insulating material. The stationary contact members shownin Fig. 1 are shown in Fig. 2 herein supported by and movable onmetallic rods 35 and 36. Rods 35 and 36 are insulated from each other.

Members 39 and 40 support rods 35 and 36 respectively and are ofsuitable insulating material. This arrangement is especlally adapted tobalanced circuit arrangements and more particularly to amplifiercircuits. Contact members 37, 37, 37b and 37 are positioned on rod 35.Contact members 38, 38", 38b and 38c are positioned on rod 36. Mov-yable contact members 23 of coil 1 are shown engaged with contact members37 and 38. Contact members 37, 37 b and 37 and contact members 38a, 38band 38 are positioned to engage with contacts of coils 2, 3 and 4 shownin Figs. 3. and 4.

Figs. 3 and 4 show side and front elevations respectively of theinductance system of my invention. In Fig. 3 the arrangement is thatadapted to balanced circuit arrangementswvherein supporting members 39and 40 are mounted on sockets 41 and 43, respectively. Sockets 41 and 43retain thermionic tubes 42 and 44, respectively. KA cooling liqf uidcirculating through sockets 41 and 43 may also circulate through theseveral coils of the inductance system. Condenser 45 is ositionedbetween sockets 41 and 43. In ig. 4 a front elevation in part section isshown. Reference characters correspond to those of Fig. 3. The coils ofinsulating tubing and inductance coils are shown interconnected bytubing members 16, 17 .and 18.

Many modifications of the inductance system of my invention arepossible. The end turns of the coils of insulating tubing may befastened to the shaft, a large loop of the hose permitting the shaft 11to turn freely and maintaining a continuous fluid path through the hoseat the same time. The end of the loop may be held by a cli which issupported from the main frame o the transmitter. The insulating tubingcoils 20 and 21 may be wound in such a manner that their respectiveturns are side by side with both inlet and outlet to the system locatedat one end of the shaft.

I realize that many modifications are possible without departing fromthe spirit of my invention and it is to be understood that theembodiments of my invention are not to be limited by the foregoingspecification or by the accompanying drawing but only by the limitationsimposed by the appended claims.

Vhat I claim as new and desire to secure by Letters Patent of the UnitedStates is as follows:

1. An inductance system comprising in combination a plurality ofindividual inductance coils, said inductance coils comprisin lengths ofmetal tubing, said coils supporte by a common framework, a shaftsupporting and adapted to rotate said framework and individual lengthsof insulating tubular members interconnecting said coils.

2. An inductance system comprising in vtances adapte with an externalcircuit, said inductances combination a plurality of individualinductance coils, said inductance coils comprising lengths of metaltubing, individual lengths of flexible fluid conducting membersinterconnecting said individual coils and means 4. An inductance systemcomprising in combination a plurality of individual helical memberscomprising lengths of metallic tubing having associated contact members,individual lengths of insulating tubing intercone necting said helicalmembers and lengths of flexible tubing adapted to connect said helicalmembers With a source of cooling liquid.

5. An inductance system comprising in combination a plurality ofinductances mounted on a rotatable framework, said inductancesconsisting of metal tubing, insulating tubing interconnecting saidinductances and flexible tubing adapted to associate said inductanceswith a source of liquid.

6. An inductance system comprising in combination a plurality ofindividual inductances mounted on a rotatable framework, saidinductances comprising metallic tubing and insulating fluid conductingmembers interconnecting said inductances.

7. An inductance system comprising in combination a plurality ofindividual inductances adapted to be selectively associated with anexternal circuit, said inductances comprising individual tubularelectrical 'conductors and fluid conducting members interconnecting saidinductances.

8. An inductance system comprising in' combination a plurality ofindividual inductances adapted to be selectively associated with anexternalv circuit, said inductances comprising individual tubularelectrical and fluid conducting members and interconnected by membersadapted to convey fluid between said inductances and provide arelatively high electrical resistance between said ind 1ctances.

9. An inductance system com rising in combination a plurality of indiviual induen tances adapted to be selectively associated with anelectrical circuit, said inductances comprisingindividual tubularelectrical and fluid conducting members and interconnected by individualfluid'conducting members having a high electrical resistance.

10. An inductance system comprising in combination a lurality ofindividual induc-` to be selectively associated comprising individualtubular electrical and fluid conductin members and interconnected byflexible flui conducting members yhaving a high electrical resistance.

LOUIS A. GERHARD.

